News and information about wildlife in and around the parish

Westbury Moth, rather than Butterfly, of the week 5th August

   Hummingbird Hawkmoth:  This day flying moth is quite unmistakeable. It has a smart grey brown body with white markings along the sides and orange hind wings. With a 5cm wingspan and its continually whirring wings it makes a characteristic ‘hum’.  Part of its scientific name is Macroglossum which recognises that it has a very long tongue which enables it to collect nectar, while hovering, from long tubular flowers like honeysuckle and red valerian.






It is a regular immigrant but is now managing to overwinter, especially in the south west of England.  It is a resident moth of Southern Europe and North Africa and is found across Asia as far as China and Japan.  In southern Europe it has two or three generations each year and over-winters as an adult hidden in a crevice.  It is a strong flier and variable numbers come into the UK from France and Spain every summer maybe as early as April but particularly in July and August and lay eggs particularly on lady’s and hedge bedstraws.

Lady’s Bedstraw

The caterpillar is a characteristic green with the hawkmoth spike at the tail end.  These home-produced moths are seen in September and October and an increasing number seem to be over-wintering successfully.  This is another animal we are seeing more of because of global warming.  There is a row for recording this moth on the Westbury Garden butterflies recording sheet.


Photos Robert Maxwell Wood   John Ball   Peter Bright

Butterfly of the Week 29th July 2020

Small Copper:  This handsome, brightly copper-coloured, small butterfly lives up to its name.  It is about the same size as a common blue.  It is widely distributed and found in a great variety of habitats across the wider countryside, where its chief food plant – common sorrel grows.  Woodland rides, hedgerows, arable set aside, parks, gardens, and churchyards where it is relatively dry and open, and which contain suitable nectar sources.


They are, usually, only a few adults on the wing at the same time in their favoured sites.  They over-winter as caterpillars which go into hibernation by the middle of October.  In the following March, these caterpillars complete their development and pupate in April, after which the first generation emerges in the latter part of May or early June.  The males are territorial chasing away other males and checking out any passing females.  Eggs laid by this first generation, go through to pupate in late June and July such that the second generation emerges at the end of July and into August. These are the butterflies on the wing now.



A third generation is then produced which emerges in the latter half of September.  It is this third generation, which can appear in large numbers in favourable years, as in Westbury in 2018 after the long hot summer.


Photos  Mick Fletcher      John Ball        Peter Bright

Butterfly of the Week 22nd July 2020

Chalkhill Blue:   This elegant butterfly, somewhat larger than the common blue, is confined, as its name suggests, to unfertilised chalk and limestone short grasslands.  Ideally, and perhaps nearly essentially, rabbit grazing to create this short sward height is important.  Certainly, scrubbing up of such habitats, as rabbit numbers have reduced, is connected to reduction in Chalkhill blue numbers.  There may also be climate effects as many populations are struggling, at the moment, across England.  The male is a stunning and unmistakeable milky blue colour while the females are milk chocolate brown.  Both male and female have conspicuous dark lines through the white fringes on edges of the wings that the smaller common blues do not have.  The butterfly is entirely dependent on horseshoe vetch which is, in turn, dependent on suitable grazing to keep the sward relatively short.

Horseshoe vetch flowers obviously in late May but otherwise the fine leaves of the plant are very inconspicuous. The caterpillars are also dependent on attendant ants that they supply with attractive secretions, who, in turn, benefit significantly from these as a food source.  When the butterflies emerge in mid-July and perhaps flying into September the males are particularly conspicuous covering the colony area searching out unmated females.  These females can be inconspicuous but are easily found nectaring on suitable plants such as marjoram and knapweeds and show off the dark lines through the white fringes of their wings.  The eggs are laid on or near the foodplant but seem to fall easily to the ground, where they are invisible in the chalk or limestone rocky soil, and they spend the winter at this stage.   The egg hatches in the following April and the young larvae begin their mutual relationship with the local ants such as the Yellow Meadow ant while feeding on the horseshoe vetch leaves and later flowers.  It is possible that pheromones from ant trails help determine exactly where the female butterflies lay their eggs.  The pupa is formed in June or July and is probably buried by its ant partners that are still collecting its secretions.  Like other Lycaenids the pupa is believed to make ant-attractive sounds!   The single generation is then ready to emerge in late July and onwards.  In Somerset, Chalkhill blues are confined to the Mendips from Wookey Hole Fields to Brean Down and to the reserves on the Poldens.  Most of the sites are in Nature Reserves of one sort or another where suitable grazing can be maintained.  We are fortunate – if you want to see this spectacular, and Near Threatened, butterfly, that Westbury Beacon, Stoke Camp and Draycott Sleights are all good sites even if numbers have fallen in recent years.  They could also be expected on Deerleap and Cook’s field if the food plant survives there as well.  Please let me know if you see any, particularly in out of the way places!

Photos  Peter Bright

A Quartet of Westbury Butterflies for the Week 15th July 2020

There are 4 hairstreaks that have been seen in the Parish of Westbury, but they are all rare and, maybe, particularly hard to notice as well.  Green hairstreaks are over, Purple and White-letter hairstreaks are flying now and Brown Hairstreaks fly from mid-August into September.

  Green Hairstreak:   The butterfly overwinters as a pupa, unlike the other hairstreaks that over-winter as eggs.  These handsome bright green adult butterflies emerge from mid-April through to the beginning of June.  It is the underneath of the wings that are green and, settling with wings always closed, you do not see the brown upper sides of the wings.   They do well in areas with scrubby vegetation mixed with shrubs.  The males are territorial flying out to investigate any passing butterfly for females.  The eggs can be laid on a wide variety of food plants such as bird’s foot trefoil and common rockrose, and on the shrubs buckthorn, dogwood and gorse.




By the end of July, the caterpillars are fully developed, and the pupa is formed hidden at the base of the vegetation.  Like other members of the Lycaenid – Blue Family, there is some relationship with ants, and it is perhaps as pupae that the ants offer some protection.  The pupa is reported to squeak just like an ant!

Photos  John Ball    Peter Bright



White-letter Hairstreak:  This is the rarest of this quartet and has suffered greatly from the loss of elms from Dutch Elm disease.  It is entirely dependent on elms and has a preference for Wych elm.  The adults, about the size of a common blue,  emerge in late June and can fly for the whole of July.  They feed on aphid honeydew and can spend their whole life at the tops of elms and so be almost invisible.  Some may come down to visit flowers at ground level in the early morning or late afternoon as do Purple Hairstreaks.

The adult butterflies rest with wings closed showing the white W that gives it its name.  It has tails and eyespots on the hind wings which is believed to protect it from fatal bird attack with some flying butterflies being seen with this part of the hind wing missing.  The eggs are laid on small twigs of any of the various elms and it is in this stage that it overwinters.  The newly emerged caterpillars feed high in the canopy during March, April and May, and pupate in late May or early June to emerge at the end of the month.  One was seen in Westbury in 2011 and another in 2019 and there are regular reports from Lord’s Wood near Pensford, but there is nowhere you can guarantee to see them.

Photo  Peter Bright



Purple Hairstreak:  This is a butterfly of oak woods or even single oak trees.  During June and early July, the pupae are formed in the vegetation at ground level below oak trees.  It may be that at this stage as well as a caterpillar, that there is some relationship with ants to which they can ‘sing’!

The adults emerge from pupae at ground level and having expanded their wings fly up into the oak tree canopy.

There, the silver undersides of the flying butterfly can be seen flashing in the sunlight high in the tree.  The upper surfaces of the wings have a purple sheen that shows as they bask in the sunshine.  They are a little larger than common blues.  The adult butterflies can spend their whole life high in the canopy feeding on aphid honeydew and mating out of sight of human observers.  They are reported to come down to ground level to nectar on flowers in the early evening so are hard to find at ‘normal butterfly times’ in the middle of the day.

The eggs are laid at the base of oak buds and it is at this stage they over-winter. The following March, April, and May the caterpillars feed inside the developing buds later transferring to eating the young developing leaves at night after resting camouflaged on the twigs.  Fully mature at the end of May the caterpillar descends to ground level once more.  This is the most abundant of the hairstreaks but being so hard to see its distribution and numbers are extremely hard to gauge accurately.

Photo    Mick Fletcher  John Ball   Peter Bright  Simon Bright



Brown Hairstreak:  This handsome butterfly is the largest of the hairstreaks being about the size of a gatekeeper.  It is a butterfly that depends on Blackthorn and needs 2 and 3-year-old young shrubby growth on which it lays its eggs in late August and September.  Flailing of blackthorn hedges every year is a disaster.

Management for Brown Hairstreaks means cutting blackthorn back on a 3-year cycle.  They overwinter as eggs and the easiest way to detect the presence of this elusive butterfly is to look for the bright white eggs laid in the forks of small twigs.  On hatching in early May, the caterpillar feeds inside the young leaf buds but transfers to eating the young leaves as they appear in May and June.  The pupa is formed in July in the ground and it seems that it may be buried by ant activity in a cell of dry earth.  The adults emerge in August and September.  The males gather in assembly trees such as tall hedgerow ashes feeding on the aphid honeydew and waiting for the visiting females.  After mating the females search out suitable blackthorn so that they are the ones that people come across easily at human eye-level.  The males rarely come down from the tall trees where they spend their time and so are hardly ever seen.



Several Brown Hairstreaks have been seen in the Village but on the lower parts facing onto the moor.  It is reasonable to speculate that there are colonies in the Parish somewhere on the hedgerow blackthorns that are not cut every year.  The Somerset strongholds are in the centre of the county around Taunton.

Photos  Peter Bright

A Trio of Westbury Butterflies of the Week 8th July 2020.


Comma:  This is really a woodland butterfly that has had times in the past when it became quite rare.  However, since the 1960s it has increased dramatically in numbers and has spread northwards reaching Scotland in 2000.  It is now a familiar butterfly of woodland edges, hedgerows and gardens.  The butterfly is named for the white mark on the underside of the hind wing though on the other wing it will resemble a C which is part of its scientific name, Polygonia c-album.  The adult butterfly overwinters, presumably in sheltered places in its woodland habitat but not in our garages and outhouses.  On emerging from hibernation in late March or early April the males take up territories investigating any passing butterfly looking for females.  Pairing is believed to take place high in the woodland canopy after which the female prospects for suitably sunny but sheltered food plant.  In the past a much used foodplant was hop but now the main food plant is nettle but it has been found on a variety of plants such as currants, elms and willows.  The caterpillar feeds inconspicuously on the underside of the leaves of its food plant but by the time it reaches the last, 5th instar, its colouring has been transformed such that it now camouflaged looking like a white bird dropping.  The pupa is formed hanging amongst the vegetation of its food plant.  The adults of the next generation emerge in late May or early June.  These come in two forms – the normal darker form and a much paler form, hutchisonii.  The normal form feeds up on nectar and goes into hibernation in August.  The paler, hutchinsonii, mate and lay eggs that go through their caterpillar and pupal stages emerging in late August and September as a second generation.  These are the late season butterflies which will then, themselves, go into hibernation in late September or October.  There is, therefore, a mixture of one and two generations in its life cycle.

Photos   Robert Maxwell Wood    Peter Bright

Silver-washed Fritillary:   This magnificent, bright orange insect is close to the largest British butterfly and is certainly the largest in Somerset now.  This colouring is also why in some parts of the world this group of butterflies are called leopards. It is a butterfly of woodlands that have an abundance of violets growing around the moss-covered bases of trees, particularly oak.  Woods that are coppiced or thinned have an abundance of bramble, a favourite nectar source, as well as encouraging a good growth of violets. 

They spend a lot of time high in the canopy and feed on the abundance of honey dew on the leaf surfaces.  In some years these strong flying butterflies come into gardens using plants like Hebe and Buddleia as convenient nectar sources. The adults emerge in late June or July and may continue to fly into the middle of August.  They are fast and powerful fliers and the males patrol the woodland rides and canopy investigating any orange butterfly checking for virgin females.

If such a female is found there is a spectacular courtship flight with the male showering the female with pheromones from the sex brands on the front wings that show as dark lines along the middle two veins.  Following this the female seeks out patches of violets but having found them, then goes to a nearby mossy covered oak trunk base where she lays eggs, singly, in mossy crevices.  There is a fabulous colour variation of the females which is a deep bronze green colour called valesina.

It is possible that this dark colouration is favoured in poor summers as the butterfly warms up more quickly, but it is at a disadvantage in normal summers as the males take longer to find these unusually coloured females.  The newly emerged 1st instar caterpillar eats its way out of the egg and immediately hides itself in a bark crevice where it passes the winter.  This could be why ash and beech woods are unsuitable lacking the appropriate moss filled bark crevices.  From early April the young caterpillar comes down to the woodland floor and feeds on the nearby violets.  When fully grown the caterpillar goes up a nearby plant to pupate a metre or two off the ground.  The next generation of adults emerge in late June providing another spectacle of summer in Mendip woodlands.

Photos    Peter Bright


 Dark green Fritillary:     This is typically a butterfly of windswept limestone grasslands but is also found on bracken covered hillsides, grassy dunes and a variety of similar habitats.  It is named for the green wash on the underside of the hind wings.  They need the sward to be of medium height so that heavy grazing, or complete lack of such, can make the violets that are its caterpillar food plant unsuitable.  It should be much more widespread across the Mendip scarp than it is but, it is doing well at Ubley Warren.   Single individuals have been seen on the Beacon and even in a Westbury garden over the last few years. 

With suitable grazing and clearing of gorse there is hope that the butterfly will return to the Beacon once again.  The adults emerge in June and will fly for much of July and perhaps into early August.  They fly strongly and can cope with their windy habitat and have a special fondness for purple flowers like knapweed as nectar sources.  The males will patrol large areas searching for virgin females investigating any suitably coloured butterflies.  After mating, the females will hide while their eggs mature and will then search out the violets growing in suitable places before laying near to them.  As with the Silver-washed Fritillary, the newly hatched caterpillar immediately finds a hiding place in which to hibernate.  Towards the end of March in the following year the caterpillar emerges from hibernation and seeks out violets on which to feed.  The later instar caterpillars are particularly black and spiky and may be seen travelling across open spaces seeking new supplies of violets. 

The blackness presumably enables the caterpillar to warm up quickly in its otherwise exposed and cool habitat. In a very tall grass sward it may, therefore, not be able to warm up quickly enough to survive.  In the middle of May or beginning of June the caterpillars will find hidden places to pupate and the adults will start emerging again from the middle of June.

Photos   John Ball    Peter Bright  Georgina Shuckburgh

Lynch Lane Sunshine, Maximum and Minimum Temperatures and Rainfall for 2006 to 2020

Below are links to the data for the months March to June inclusive.  July and August will be added as we get there. The data for March to May have been posted earlier but you would have to chase about to make comparisons between months.  There is a separate file of Photo-voltaic generation totals for each month since 2010 which is a proxy for amount of sunshine.  An attempt is made to suggest which of the years has been sunniest and in which months.


2020.4.5 March max min rain and sunshine data 2006 to 2020  

2020.4.30 April max min rain and sunshine data 2006 to 2020

2020.6.1 May max min rain and sunshine data 2006 to 2020

2020.6.30 June max min rain and sunshine data 2006 to 2020

2020.6.30 Monthly kWh totals 2010-2020

Two brown Butterflies of the week 1st July 2020


Ringlet: This is a butterfly of the wider countryside whose caterpillars depend on the tall grasses of sheltered and damper places like hedgerows, field margins and woodland rides. It is one of the British butterflies whose numbers have been increasing and whose distribution has been expanding over the last 30 years. It is suggested that global warming and the reduction of pollution are both contributory factors. Reduced grass cutting of roadside verges and in places like churchyards are likely to be beneficial. The adults begin emerging in late June and this continues throughout July. The freshly emerged butterfly is a uniform rich dark chocolate colour with conspicuous white fringes to the wings. There are rows of spots on each wing which are most conspicuous from underneath with white centres surrounded by a yellow ‘ring’ which gives the butterfly its name. There is quite a lot of variation in how many spots and the brightness and shapes of the rings. They can resemble male Meadow Browns with which they often fly but lack the yellow patches on the underneath of the front wings and are a dark chocolate colour to the Meadow Brown’s milk chocolate! Males patrol the tall damp grass habitat searching for females. After mating the females lay eggs singly perhaps being selective of the dampness and condition of the grasses before seemingly scattering their eggs. The caterpillars are slow growing and when they reach the third instar in the autumn hide themselves away, overwintering in the bottom of a grass tussock. In the following spring they start feeding again and continuing their slow growth. By the beginning of June, the 5th instar caterpillar forms a pupa hidden at the base of its grass habitat. After some two weeks the mature butterfly is ready to emerge. There is only one generation each year.

Photos Tina Westcott     Peter Bright

  Gatekeeper: This butterfly is found in all sorts of ‘hedgerow’ habitats using the grasses growing in the more shaded parts for their caterpillars to feed on. Brambles are a favourite nectar source. It obviously lives up to its alternative names the ‘Hedge Brown’ as well as ‘keeping gates’ in hedgerows. The butterfly is smaller than a Meadow Brown and is a much brighter orange colour. The males have a dark sex brand in the orange of the forewing which the slightly larger females do not have. The big eyespot on the forewing has two white spots to the Meadow Brown’s single one and on the underside of the hind wings the spots are white rather than black as they are in the Meadow Brown. Overall, it is a very handsome and almost unmistakeable butterfly. The first adults emerge in late June and may continue to emerge until late August.

The males are territorial chasing up any passing butterflies to check for females. After mating the female selects finer grasses growing in the shade of shrubs and inside hedgerows as egg laying sites. After hatching the caterpillar feeds and as a second instar hibernates hidden in the fold of a leafy tussock. In the spring the caterpillar continues feeding and growing and pupates in early June or later to emerge once more in late June or into July and August. There is thus only one generation each year. Look out for them now as they are just appearing.

Photos      Peter Bright

Westbury Butterflies Small and Essex Skippers

These two skippers will be flying for the next few weeks and provide a real challenge to distinguish between them.  The only feature that is clear is the colour of the underside of the ends of the antennae!  Needless to say they rarely pose to suit you as the observer.  If you can get a photo graph in which the butterfly is looking straight at the camera as in these two photos it is usually easy!  The Essex Skipper looks as if it has dipped the underneath of each antenna in black ink.  In the small skipper the same patch is orange or streaky orange and blackish.  If you have a male the sex brand on the top of the forewing in the Essex is shorter and straight whereas in the Small it is longer and a bit curved!  I would be keen to see whatever pictures of these skippers you might be able to take – however fuzzy.

Two Butterflies of the past month

 Small Blue: This diminutive little butterfly is, along with Grizzled Skipper and Brown Argus, Somerset’s smallest butterflies. It belongs to the Blue family though its ‘blueness’ is more steely grey in males and plain brown in the females. In flight it looks silvery from the undersides of the wings being particularly conspicuous. The only food plant is kidney vetch. This plant grows well in unimproved limestone grasslands where there is some disturbance keeping the vegetation sparse providing opportunities for the kidney vetch to spread. The butterflies need some nearby scrub for the adults to collect nectar to rest and find each other. They will happily land on people to pick up the salts on our skin. Typically, these scrubby areas are in sheltered spots at the bottom of south facing slopes while the kidney vetch grows on the much more sparsely vegetated slopes nearby. The adults usually emerge in late May or early June and can be seen basking and courting on bramble or other scrubby plants.


The females then seek out suitable kidney vetch flower heads in which to lay a single egg. The caterpillars are cannibalistic so there is benefit in egg laying females to make sure that an egg has not already been laid in a flower head as the larger caterpillar will eat any smaller ones. The larvae feed in the flower head going through 4 instars and by July are fully grown. The earliest 4th instar caterpillars may pupate and go on to produce a limited second brood in early August. However, most will seek a place to over winter presumably hidden at ground level. In the following April or May, the larva will pupate and be ready to emerge in late May or early June once again. It is not a butterfly of the Wider Countryside being confined to sites managed for the kidney vetch. There are very few colonies in Somerset, but we have two of the best at Stoke Camp and Draycott Sleights. For an unusual place try the Odd Down Park and Ride car park which apparently has a thriving colony and presumably a good growth of suitable kidney vetch.

Photos   John Ball   Peter Bright


Small pearl-bordered fritillary: Like the Small Blue this is a butterfly of Nature Reserves.  In this case they are managed for the scrubby, bracken covered somewhat moist grassland and woodland edge habitats where suitable violets grow well. On Mendip the adults emerge at the end of May and into the first two weeks of June. The males will patrol tirelessly searching for virgin females. They will visit a wide variety of flowers as nectar sources. Once mated the females will seek out suitable mats of violets growing in relatively damp and lusher areas to lay their eggs. The eggs are laid singly and not necessarily on the violet leaves but sometimes just nearby.  The caterpillars go through 5 instars but by the end of the summer in the 3rd or 4th instar they go into hibernation.   The following spring, they will continue to feed and after the 5th instar will pupate by the end of April, and will emerge in late May or early June as the fresh and beautiful butterflies they are. There are a variety of sites across Mendip where they can be seen from Crook Peak, Doleberry Warren, Shute Shelf, Ubley Warren and Priddy Mineries. They have recently disappeared from the Blackdowns in South Somerset but have strong colonies in and around Exmoor.

Photos   Peter Bright


Butterflies of the Week 24th June 2020



Common Blue: This is the familiar blue of the wider countryside and, indeed, is common. The males are a bright sky-blue colour whereas the females may have a lot of blue scales or these blue scales may just be confined to the body so that they look generally brown. It is these brown females which can look like Brown Argus except that the Brown Argus is distinctly smaller and has some differences in the underwing spotting pattern. Mature, 4th instar caterpillars emerge from hibernation in April and pupate. The first-generation adult butterflies will then emerge in May and early June. The fertilised females seek out bird’s foot trefoil on which to lay their eggs. Like most ‘blues’ the caterpillars have a honey gland which makes them attractive to ants which provide a measure of protection from some predators. They are, however, nowhere near as dependent on ants as the Large Blue. The caterpillars will develop and then pupate in July and the second-generation butterflies will emerge in August. The offspring of this second generation may, in favourable years, go on to produce a third generation which will emerge in late September. Otherwise the mature larvae will overwinter hidden amongst vegetation.

Photos   Peter Bright   John Ball




  Brown Argus: This diminutive butterfly is, along with the small blue, our smallest butterfly. Newly emerged adults are a rich brown colour and the orange crescents of spots show up clearly. In females the orange spots reach the front of the forewing whereas, in males, they fade out little more than halfway to the front edge. Its resemblance to brown versions of the female common blue can cause confusion. However, it is distinctly smaller and has no hint of blue scales on the wings or body, and, for those with a photo, the underwing spot patterns are distinctly different.   This butterfly is a warmth loving species active in sunshine and in warm sheltered sites. The first generation emerges in May and early June. After mating the females seek out suitable food plants on which to lay eggs. In the past common rockrose was the main food plant and was why the butterfly was confined to sites with this plant. However, recently the butterfly now also uses common stork’s bill and other close relatives like dove’s foot cranesbill. This change of food preference and the increased temperatures of global warming have resulted in this butterfly spreading northwards again and recolonising many habitats from which it had been excluded by loss of common rock rose. The eggs laid in June will produce caterpillars that pupate in July with the second generation emerging in August. It will be the caterpillars from this second generation which will overwinter as a more or less mature caterpillar.  Emphasising that it is a ‘blue’ that happens not to be blue the caterpillars are attractive to ants just as with its close relative the common blue.

Photos     Simon Reece     Peter Bright